Former al-Qaeda affiliate Jabhat Fateh al-Sham has ejected divisive militant group Jund al-Aqsa from its ranks in Syria, following clashes with other rebel groups in the opposition stronghold of Idlib.

The move came after clashes broke out between the major Salafist opposition group Ahrar al-Sham and Jund al-Aqsa. Over the weekend, Ahrar al-Sham - with the backing of a number of allied rebel groups - began an operation to "annihilate" Jund al-Aqsa, which they have long accused of being a front group for the Islamic State.

Jabhat Fateh al-Sham, formely known as the Nusra Front, have established themselves as the major force in Idlib. Rebel leaders have expressed anger at Jabhat Fateh al-Sham's decision to incorporate Jund al-Aqsa into its ranks in October and have blamed JFS for failing to control Jund al-Aqsa factions during the weekend's violence.

On Thursday, JFS launched a series of assaults on Ahrar al-Sham's headquarters, checkpoints and a border crossing in the town of Khirbet al-Joz, near the Turkish border. Other attacks were reported in a number of nearby towns, including outside the strategic city of Jisr al-Shughour.

The attack came after JFS alleged that Ahrar al-Sham had held an Iraqi JFS commander in one of its jails.

Fighting continued over the weekend, with most of the violence centred around the mountainous region of Jabal al-Zawiya. There were numerous reports of casualties and prisoners being taken on both sides.

On Sunday, Ahrar al-Sham and Jund al-Aqsa signed a peace agreement, agreeing to release captured prisoners and set up council for mediation.

However, the incident left a bad taste in the mouth of many opposition supporters who see Jund al-Aqsa as a fifth column, and worry about being disunited even as ceasefire talks began in the Kazakh capital Astana. Following the expulsion of Jund al-Aqsa, violence was reported to have restarted:

A statement released by Ahrar al-Sham's Shura Scholars Council on Monday called on JFS to either control Jund al-Aqsa properly or stop protecting them.

"Fateh al-Sham committed itself to prevent the gang of Jund al-Aqsa from their aggression when they gave pledge to JFS, and tricked factions about its ability to control them and take on their hands, so factions accepted in order to preserve the arena and prevent chaos," said the statement.

"But it has not fulfilled that pledge at all, and we have asked JFS to fulfill its promise or lift the protection of Jund al-Aqsa."

The expulsion comes as talks begin between opposition representatives and the Syrian government in Astana. Though Ahrar al-Sham has stated that it will respect the decisions made by the delegation, neither it nor JFS agreed to participate in the talks which they view as capitulation, coming as they do after the crushing of the rebel forces in Aleppo in 2016.

Some analysts have suggested that Ahrar al-Sham refused to take part in order to avoid being an accessory to the international isolation of JFS which, due to their links with al-Qaeda, have been excluded from peace talks.

However, such an approach could be highly risky, potentially pushing the organisation into irrelevence.

"[Ahrar al-Sham's] current policy of having one foot within the mainstream opposition and another in al-Qaeda is no longer tenable," wrote Hassan Hassan for the United Arab Emirates newspaper the National on Sunday.

"As JFS and mainstream rebels drift further apart, Ahrar al-Sham’s attempt to keep a foot in each camp will further rip it apart."

He added that the refusal to take part was particularly "embarrassing and disappointing" considering they announced their intentions only a day before their headquarters were stormed.

Both JFS and Jund al-Aqsa have been targets of Russia and American air strikes, which has raised concerns about their proximity to other rebel groups and civilians.

Elsewhere in Idlib, it was reported that JFS had surrounded the positions in western Aleppo of rival opposition group Jaish al-Mujahideen, which had also been part of the Ahrar al-Sham led efforts to target Jund al-Aqsa.